Leaving Your Laptop Plugged in Harms its Battery?

There has always been a tight controversy between keeping a laptop packed with the battery plugged-in at all times, or not. Many have wondered if this overcharging process, if we are allowed to call it so, may reduce the battery life over the years or, even damage the product in some way. As a laptop owner myself, I had troubles choosing a side but, after a long search on the web, I have gathered all the results I have found under the same roof and today, I’m about to make them public.

Taking a deep plunge into the mystery which has wrapped many laptop users in darkness, by not knowing whether they should keep their device plugged-in with/without a battery or simply use it as a smartphone, and charge it whenever the energy is depleted, we set ourselves to present the most relevant motives of each side, while helping you take a decision, by yourself.

How should a laptop battery be used

Although highly unlikely, you may not be aware of the damages brought over the years to a plain old laptop battery. In some cases, depending on the manufacturer of the battery and even of the one that assembled the laptop, a brand new shiny product which was guaranteed to supply between two and three hours of juice on a regular charge can degrade very fast. We have heard cases when laptops, mostly from Dell, had a battery so bad that after a year, the user could only squeeze around 5 minutes of life – meaning that he would have to use a power outlet at all times.

Besides on the pure use of a battery, there are also other factors which influence the long-life of this product, like the laptop’s own settings. If the manufacturer was so kind to include power saving modes or settings to stop the battery from charging when it’s above 93%, let’s say, then you are in luck. If not, here’s a tale of the most known theories and how you must react:

Exercise the battery – as a product meant to be used, the battery should not be kept in dark place for a long time, without being drained once in a time. Those who wish to use the laptop solely on the power transmitted directly from the AC plug, should insert the battery at least once in a month, let it charge and then drain it up to 15%. This will ensure that the battery is getting some action from time to time and the chemical substances within will surely appreciate it.

Store the battery when stationary – those who are certain that they are not going to use the battery in the next couple of months, because they rely just on the power plug, without moving the device at all, should best charge the battery until 33%-40% of the maximum juice and then store it inside a refrigerator or a cold place (but not colder than 32F or 0 Celsius). If the battery is taken out of the fridge once in a while it will damage the product more than ever.

Don’t let it discharge completely– a fact that I wasn’t aware of until a couple of hours ago was that whenever the laptop battery went under the 15% mark, it suffered quite some complications. It seems that it is mandatory to shut down the equipment or plug it under this limit, this being the main reason why batteries are slowly killed. Moreover, if a battery is discharged below the 5% mark or even completely, permanent faults will occur and the product looses a significant amount of capacity. Discharging completely is only allowed on older batteries (not Li-ion) with memory effects.

Using the laptop while charging the battery – the myth that a battery will have to suffer under these circumstances is absolutely busted, at least for notebooks. While charging, a part of the juice will go into actually powering the device while the spare will be instead into replenishing the battery. The only disadvantage is that the cells will be recharged slower.

Fast batteries can be somewhat fixed – those with batteries that die out prematurely can be somewhat saved, by leaving to power the laptop until the operating system complains, pulling it and recharging it, but only after the battery has cooled down. The recharging process must be done while the laptop is offline, to avoid any extra thermal stress. Repeat the procedure a couple of times and improvements should be seen.

Laptop battery cycles

Just like we’ve explained in a previous article – Why has iPhone’s battery life remained the same – every battery has a life cycle. Thus, if your iPhone can last for, say, 400+ recharge cycles, then obviously, your tablet’s or laptop’s battery will also have a similar thing. Here’s another explanation:

You shouldn’t technically leave your laptop plugged in all the time, but you certainly don’t need to deep-cycle it a few times a week. Furthermore, the recommendation for monthly battery usage isn’t just for capacity preservation: it’s mostly so the charge indicator can maintain accuracy as the battery’s capacity decreases naturally over its lifespan.

Therefore, when you buy a laptop, don’t just look at how many hours its battery can last, but also check how many cycles it actually has. Remember, a cycle is from 100% fully charged to completely depleted. A moderate use, it seems, will make your battery degrade by 30% during a year and the battery should “live” for about 350 charging cycles. But, this is just a ballpark figure.

Should the battery be kept inside the laptop or not?

Indeed, that is the question. After acknowledging all the advices presented above, the short conclusion is that you should definitely keep the laptop battery plugged at most times. This will ensure that the product is exercised and because many laptops have a stop-charge function, which protects the product from overcharging (when the level reaches 90%, the power will be switched from charging the battery to supplying the laptop, and the charging process will stop) the battery will be kept safe. While the battery is inside the laptop, the following things will happen though:

High charge – unfortunately, the 90% mark is a bit too high for a battery. As we’ve mentioned earlier, an almost half percentage is ideal for this kind of product. While the battery is stored with this high charge, chemical process will react faster and the aging of the product will happen a bit faster.

High temperature – because the battery is situated to a 60 degrees hot laptop, the heat will disperse onto the battery itself, forcing it to degrade faster and making it lose precious life. Vice versa, the high charge of the battery will translate into higher temperatures that will heat the laptop itself.

Although these two disadvantages cannot be overlooked, they usually damage the battery less than in cases where the product is not used. I have been using this tactic in the past four years and it has not failed me yet. Moreover, it protected me when power outages occurred. How about you? Do you keep your laptop battery at all times?

Alex Serban Feature Writer Alex holds an engineering degree in Telecommunications and has been covering technology as a writer since 2009. Customization is his middle name and he doesn’t like to own stock model gadgets. When he’s away from the keyboard, simpler things like hiking, mountain climbing and having a cold drink make his day.